The repair and maintenance of railroad rights of way have always been of prime consideration to ensure safe and reliable passage of passenger and freight trains. The railroad tracks upon which these trains travel are subject to frequent and heavy traffic and loading. The cost of maintaining these tracks also is commensurate with such traffic and requires significant expenditures for materials as well as labor for installation of the materials.
In particular, railroad companies constantly engage in such maintenance activities as replacing worn cross ties or the rails which they support. Typically, the worn cross tie or rail must be removed from where it is installed, and then a new cross tie or rail must be fitted and ultimately installed in place of the worn member.
Installing a cross tie involves positioning a tie on the railway bed and mechanically vibrating the surrounding ballast or stone so that the ballast flows around the tie providing support and resistance to tie movement.
Once the cross tie is placed, the rail then must be fastened to the cross tie. Typically, a rail is connected to a cross tie with a tie plate. A tie plate has a slot which receives and maintains the base of the rail and holes for receiving spikes which fasten the tie plate to the cross tie.
Many devices have been advanced for automating the installation of cross ties and rails. Some devices index a tamping mechanism according to a distance traveled by the tamping mechanism along the rail. See, for example, U.S. Pat. Nos. 4,760,797 and 5,671,679.
Another device employs a CCD camera for two-dimensional, shape-from-shading or parallax based image recognition for locating the spike holes in a tie plate on a cross-tie of a railway, as opposed to the present three-dimensional, range-based surface profiling identification and verification. See, for example, U.S. Pat. No. 5,487,341.
Unfortunately, the everyday unpredictable environmental surface conditions of a railroad bed limit the ability of image recognition based systems to accurately locate target features of a railroad bed. What is needed is a method and an apparatus for identifying a feature of a railway and deploying equipment for servicing same by image processing range data pertaining to the railway feature.
The invention overcomes the issues discussed above with a method and an apparatus for identifying a feature of a railway and deploying equipment for servicing same by image processing range data pertaining to the railway feature.
The invention provides a method for servicing a railway including identifying a feature of a railway, wherein the identifying involves processing an image corresponding to ranges to the feature. The invention also provides an apparatus for servicing a railway including a vision system for determining a range to a feature of the railway and means for positioning equipment relative to, for servicing, the feature, based on the range.
The invention may be used to retrofit existing track spiking machinery to automate locating a cross tie, detecting a tie plate and spike hole thereof, and inserting and driving the track spikes into the tie plate holes into the cross tie.
The invention provides improved elements and arrangements thereof, for the purposes described, which are inexpensive, dependable and effective in accomplishing intended purposes of the invention.